As far as finding a lab, you could talk to a commercial realtor, and find out a few names of labs that do Phase I Environmental Studies (which is typically done if one is buying a commercial property).

Then talk to the labs and see who does water testing.

Survey companies may also know some labs.


Excerpt from Robert Crais' "The Monkey's Raincoat:"
"She took another microscopic bite of her sandwich, then pushed it away. Maybe she absorbed nutrients from her surroundings."